Sb/X (X = Mn, Er, Ho) Co‐Doped Lead‐Free Double Perovskite Cs₂NaInCl₆ for Single‐Component White Light Emission

Abstract Recently, the incorporation of transition‐metal ions into lead‐free double perovskite has garnered considerable attention for improving the lattice environment and enhancing photoluminescence (PL) to achieve white light emission. Here, Sb/X (Mn, Er, Ho) co‐doped Cs₂NaInCl₆ (CNIC) microcrystals (MCs) synthesized by conventional hydrothermal method are developed for single‐component white light emission with various photoinduced transition mechanisms. Sb doping in CNIC MCs causes the breaking of non‐parity forbidden transition under 360 nm laser excitation and results in blue emission; Sb/X co‐doping for CNIC MCs successfully broadens the spectrum with multi‐peak emission, which consists of unique X‐peak emission and blue emission peaked at 445 nm. The energy transfer channels from both free excitons state of CNIC and self‐trapping excitons (STEs) state of [SbCl₆]³⁻ to X ion are proved and studied by use of steady‐state and time‐resolved PL spectroscopy. Among them, Sb/Er co‐doped CNIC MCs show unique dual‐mode PL under 360 and 980 nm laser excitation. Single‐component white light emitting diode is successfully fabricated by adjusting the composition of Sb/X co‐doped CNIC MCs, which provides an alternative path for realizing single‐component white light illumination.